Socket assembly with antirotation spring washer

ABSTRACT

In a socket assembly having a housing with a closed end and an open end and an axially slidable and rotatable bearing, a spring washer seated on the axially slidable and rotatable bearing with a protrusion or a recess on the external periphery for engagement with a cooperating recess or protrusion on an inner cavity of the housing to effectively stop movement of spring washer with the axially slidable and rotatable bearing during driving conditions.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a ball joint socket assembly wherein aspring washer imparting a biasing force on an axially slidable bearingand a ball portion of a ball stud is stopped from rotation with movementof the ball stud.

Brief Description of the Prior Art

One of the difficulties with ball joint sockets is the need to prohibitsome of the cooperating internal components from rotating against eachother during steering operations. Some internal components such as thehousing cavity, cover plate and a tolerance absorbing spacer asdescribed in U.S. application Ser. No. 15/947,833 are not hardened toresist wear. As such, these components if exposed to sliding motion willwear excessively.

In the prior art, various designs have been provided to resist therelative rotation motion. For instance, the internal bearing has beensplit thus allowing for a slight interference to occur between thebearing OD and the housing cavity ID. The interference increases someresistance to rotation of the bearing but is only marginally successfulbecause it is very difficult to manage all involved variables betweenbearing and housing cavity, particularly when the bearing is subject towarpage during the hardening process. The variables work together tocreate too much or too little interference. Too little interferenceresults in not enough friction between the bearing and the sidewall toeffectively resist rotation. Too much friction can result in tight andinconsistence assembly motion. In other cases, the split internalbearing can cause fracture of the bearing and premature loosening of thesocket.

While not typical, the cover plate or even the housing cavity can behardened so that relative rotational motion will not create excessivewear but adding hardening operations creates additional cost andcomplication. In addition, hardening is not an option with the toleranceabsorbing spacer described in Ser. No. 15/947,833 which must be fullyplastic to function and, as a result, must be soft. If the internalcomponents contacting the tolerance compensating spacer rotate duringsteering actions, the spacer will wear excessively.

BRIEF SUMMARY OF THE INVENTION

In view of the above, it is an object of the present invention toprovide a socket assembly wherein a spring washer is stopped fromrotation against the cooperating internal components of the ball joint.It is another object to provide a socket assembly including a tolerancecompensating spacer which is protected from excessive wear duringdriving operations by the spring washer. Other objects and features ofthe invention will be in part apparent and in part pointed outhereinafter.

A representative improved socket assembly in accordance with the presentinvention has a housing with an inner cavity which extends from a firstopen end to a second open end. A ball stud with a ball portion and ashank portion is at least partially disposed within the inner cavity ofthe housing with the shank portion extending out of the housing throughthe first open end. An axially slidable bearing is disposed in the innercavity at the second open end. The slidable bearing has an outer surfaceengaged with the inner cavity and a bearing surface that is insurface-to-surface contact with the ball portion. There is a cover plateclosing the second open end of the housing and a spring washerpositioned on the slidable bearing for imparting a biasing force betweenthe cover plate and the slidable bearing and the ball portion of theball stud. The spring washer has at least one protrusion on an exteriorperiphery of the washer which is received in at least one cooperatingrecess in the inner cavity of the housing for use in preventing rotationof the spring washer with the axially slidable bearing. In other casesthe location of the protrusions and recesses may be reversed withrecess(es) being on the spring washer and the protrusion(s) on the innercavity of the housing. For some other applications, the protusion(s) andrecess(es) on the inner cavity may be formed as axial ridges andchannels, respectively.

While the spring washer may be oriented with a convex side facing theaxially slidable bearing, concave positioning of the spring washer onthe axially slidable bearing applies a greater resisting moment to thetwisting moment generated by the ball portion of the ball stud duringsteering actions into the bearing, thus effectively holding the axiallyslidable bearing from rotating with the ball portion of the ball studand therefore may be preferred in some cases.

Another important aspect of the invention arises when the cooperatinginternal components of the ball joint include a tolerance absorbingspacer such as described in U.S. application Ser. No. 15/947,833. Inthat case, stopping rotation of the spring washer is desirable as thetolerance absorbing spacer is relatively soft and prone to prematurewear.

In some implementations, the ball stud exits the socket through thesecond open end with first end being permanently closed In this case, aclosure ring replaces the cover plate but the spring washer operates inthe same manner as in the other embodiments.

It will be apparent to those skilled in the art that the abovedescription of the various socket assemblies forming a part of thepresent invention is at a high level and that other important elementssuch as provisions for lubricants and so forth are omitted for clarity.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In the accompanying drawings, in which several of various possibleembodiments of the invention are illustrated, corresponding referencecharacters refer to corresponding parts throughout the several views ofthe drawings in which:

FIG. 1 is a blown apart schematic view of an improved assembly inaccordance with the present invention;

FIG. 2 is a perspective view of a spring washer having a protrusion forengagement with a recess formed as an axially aligned channel in aninner cavity of a socket housing;

FIG. 3 is a perspective view of a tolerance absorbing spacer inaccordance with Ser. No. 15/947,833;

FIG. 4 is a schematic view showing force vectors on an axially slidablebearing applied by a spring washer and resisted by a ball portion of aball stud with a protrusion on its exterior periphery;

FIG. 5 is a blown apart schematic view of a second improved socketassembly incorporating a spring washer with its convex side facing theaxially slidable bearing and with a protrusion on its exterior peripheryfor engagement with one or more cooperating recess in the inner cavityof the housing (not shown) and with a protrusion on its interiorperiphery for engagement with one of a plurality of recesses formedbetween cooperating teeth on the axially slidable bearing. Recesses inthis figure are formed below the plane of the top surface of the axiallyslidable bearing.

FIG. 6 is a blown apart view of a spring washer with its convex sidefacing the axially slidable bearing and with a protrusion on itsexterior periphery for engagement with one or more cooperating recessesin the inner cavity of the housing (not shown) and with a protrusion onits interior periphery for engagement with a plurality of cooperatingrecesses in the plane of the top surface of the axially slidable bearingformed between raised teeth on the axially slidable bearing;

FIG. 7 is a blown apart view of a spring washer with one or morerecesses formed in its exterior periphery and one or more recessesformed in its interior periphery for engagement with a like number ofprotrusions on the inner cavity of the housing and the axially slidablebearing, respectively; and,

FIG. 8 is a sectional view of a socket assembly with a second open endand a closed first end a tolerance absorbing spacer and slidable bearingincluding spaces between a toothed inner ring to engage an interiorprotrusion on spring washer.

DETAILED DESCRIPTION OF AT LEAST ONE PREFERRED EMBODIMENT OF THEINVENTION

Referring to the drawings more particularly by reference character, afirst exemplary embodiment of an improved socket assembly 10(specifically a ball joint assembly) is shown in FIG. 1 . It will beappreciated that socket assembly 10 may find uses in tie rod ends, balljoints or in a wide range of other automotive and non-automotiveapplications.

With continuing reference to FIG. 1 socket assembly 10 includes ahousing 12 with an inner cavity 14 that extends from a first open end 16to a second open end 18. First open end 16 of housing 12 presents alower wall with inner surface which provides fixed bearing surface 20.Fixed bearing surface 20 is semi-spherically curved radially inwardlyand faces axially towards second open end 18 and may be integrallyformed with housing 12 or may be a second bearing part installed inhousing 12 through second open end 18.

An axially slidable bearing 22 is installed in second open end 18 and ismovable in a longitudinal direction towards fixed hardened bearingsurface 20 in first open end 16. Axially slidable bearing 22 has abearing surface 24 that has a similar curvature to a ball portion 26 ofa ball stud 28 and contacts an opposite hemisphere of the ball portion26 with respect to fixed hardened bearing surface 20 illustrated as ahardened portion of inner cavity 14. Ball portion 26 of ball stud 28 isalso surface hardened and supported between fixed bearing surface 20 (orfixed bearing) and bearing surface 24 of axially slidable bearing 22 toallow ball portion 26 to rotate and articulate relative to fixed bearingsurface 24 and housing 12.

Second open end 18 is closed with a cover plate 30 which is secured inhousing 12 with a crimped, spun-over, or welded portion 32 of secondopen end 18 after socket assembly 10 has been assembled. A spring washer34 (also called a Belleville spring) is provided between cover plate 30and a top surface 36 of axially slidable bearing 22 so as to urgeaxially slidable bearing 22 towards fixed bearing surface 20 and againstball portion 26 of ball stud 28. A tolerance absorbing spacer 38 may beinserted between spring washer 34 and cover plate 30 as shown in FIG. 1. Tolerance absorbing spacer 38 is described in U.S. patent applicationSer. No. 15/947,833 which is incorporated by reference herein in itsentirety. In brief, tolerance absorbing spacer 38 is formed as a flatannulus 40 with a plurality of wave forms 42 in the axial direction andextending around the annulus (FIG. 3 ). During assembly of socketassembly 10, tolerance absorbing spacer 38 is plastically deformed by aforce applied substantially in the axial direction leaving a controlledand desirable clearance space 44 (FIG. 8 in the assembly within whichspring washer 34 operates. Because tolerance absorbing spacer 38 isdeformable it is formed of a softer material than spring washer 34. Itis therefore desirable to stop rotation of spring washer 34 with ballportion 26 of ball stud 28 and thus prevent rotation sliding motion ofspring washer 34 against tolerance absorbing spacer 38 during steeringactions of the vehicle.

As shown in FIG. 1 , in one embodiment of socket assembly 10, springwasher 34 is positioned on top surface 36 of axially slidable bearing 22with a concave side 46 down. Spring washer 34 has a protrusion 48 on aperiphery 50 as shown in FIGS. 1 and 2 which is received in acooperating recess 52 in inner cavity 14 of housing 12 according to FIG.1 . Rotating movement of spring washer 34 is thus stopped as ballportion 26 rotates in axially slidable bearing 22. It will beappreciated that one or more protrusions 48 may be provided on periphery50 and one or more recesses 52 may be provided as channels axiallyaligned with inner cavity 14 of housing 12. It will also be appreciatedthat the elements may be reversed wherein one or more cooperatingrecesses 52 are formed in periphery 50 of spring washer 34 for receiptin one or more protrusions 48 formed as axially aligned ridges on innercavity 14 of housing 12 and that protrusions 48 may be rectangular,semicircular, triangular or the like in cross-section for engagement ofwith recesses 52 of cooperating shape.

Turning to FIG. 4 , protrusion 48 on spring washer 34 received in recess52 also tends to stop rotation of axially slidable bearing 22 withhardened ball portion 26 of ball stud 28 during vehicle steeringoperations. This rotation is undesirable, as it will cause excessivewear between the hardened axially slidable bearing 22 and (typically)soft inner cavity 14 of housing 12. The twisting moment between ballportion 26 and bearing surface 24 may be represented by the product ofcontact force (Fc ball, multiplied by coefficient of friction, thenmultiplied by distance X1). This twisting moment is resisted by aresisting moment composed of the product of (Fy, multiplied by the samecoefficient of friction, then multiplied by distance X2). Although Fy isslightly less than Fc, X2 is significantly greater than X1 and thereforethe product of the resisting moment is greater than the twisting moment.Axially slidable bearing 22 may therefore be effectively held withoutrotation by locking spring washer 34.

In another embodiment of socket assembly 10′ as shown in FIGS. 5-7 ,spring washer 34 is positioned with a convex side 54 of spring washer 34positioned on top surface 36 of axially slidable bearing 22. Springwasher 34 is a conical frustrum with an exterior periphery 50 and aninterior periphery 56. As before, exterior periphery 50 of spring washer34 may include a protrusion 48 (FIGS. 5-6 ) or recess 52 (FIG. 7 ) forengaging inner cavity 14 of housing 12 and stopping rotation of springwasher against tolerance absorbing spacer 38 when present, or againstcover plate 30. Interior periphery 56 of spring washer 34 may beprovided with a one or more recesses 52 (FIG. 7 ) for engagement withone or more protrusions 48 provided on inner top edge of axiallyslidable bearing 22 (FIG. 7 ). As shown in FIG. 6 , the elements may bereversed with one or more protrusions 48 in interior periphery 56 ofspring washer 34 for engagement with one or more recesses 52 in, orbetween raised teeth on top inner surface of axially slidable bearing22.

FIG. 8 shows a still further alternate socket assembly 10″ wherein firstend 16 of housing 12 is closed and second open end 18 allows ball stud28 to exit the housing and attach to a cooperating chassis part byvarious means. A closure ring 58 is provided at second end 18 with anaperture 60 for ball stud 28 in place of cover plate 30. This style ofjoint carries the weight of the vehicle by pushing the stud into thesocket. As with the socket assemblies 10 and 10′ discussed earlier,spring washer 34 and tolerance absorbing spacer 38, when present,operate in the same manner as the embodiments previously described.Spring washer 34 operates in controlled clearance space 44 left bytolerance absorbing spacer 38 and during assembly is positioned onaxially slidable bearing 22 and imparts a biasing force between closurering 58 and slidable bearing 22 and ball portion 26 of ball stud 28.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained. Asvarious changes could be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

1. A socket assembly comprising: a housing having an inner cavity whichextends from a first open end to a second open end; a ball stud at leastpartially disposed within said inner cavity of said housing andincluding a shank portion and a ball portion, said shank portionextending out of said housing through said first open end; an axiallyslidable bearing disposed in said inner cavity of said housing at thesecond open end, said slidable bearing having an outer surface engagedwith the inner cavity of the housing, said slidable bearing having abearing surface that is in surface-to-surface contact with said ballportion; a cover plate closing said second open end of said housing;and, a spring washer positioned on the slidable bearing for imparting abiasing force between the cover plate and the slidable bearing and theball portion of the ball stud, said spring washer having a peripherywith at least one protrusion which is received in at least onecooperating recess in the inner cavity of the housing or having aperiphery with at least one recess which is received in at least onecooperating protrusion on the inner cavity of the housing.
 2. The socketassembly of claim 1 wherein the cooperating recess in the inner cavityof the housing is at least one channel axially aligned with the innercavity or the cooperating protrusion on the inner cavity of the housingis at least one ridge axially aligned with the inner cavity of thehousing.
 3. The socket assembly of claim 1 wherein the periphery of thespring washer has at least one protrusion which is received in at leastone cooperation recess, each cooperating recess being a channel axiallyaligned with the inner cavity of the housing.
 4. The socket assembly ofclaim 1 wherein a concave side of the spring washer is positioned on theinternal bearing.
 5. The socket assembly of claim 1 wherein a convexside of the spring washer is positioned on the internal bearing.
 6. Asocket assembly comprising: a housing having an inner cavity whichextends from a first open end to a second open end; a ball stud at leastpartially disposed within said inner cavity of said housing andincluding a shank portion and a ball portion, said shank portionextending out of said housing through said first open end; an axiallyslidable bearing disposed in said inner cavity of said housing at thesecond open end, said slidable bearing having an outer surface engagedwith the inner cavity of the housing, said slidable bearing having abearing surface that is in surface-to-surface contact with said ballportion; a cover plate closing said second open end of said housing;and, a tolerance absorbing spacer formed as a flat annulus with aplurality of wave forms in the axial direction and extending around theannulus, said tolerance spacer plastically deformed by a force appliedsubstantially in the axial directed leaving a controlled clearance spacein the assembly, a spring washer positioned on the slidable bearingbelow the tolerance absorbing spacer in the controlled clearance spacefor imparting a biasing force between the cover plate and the slidablebearing to the ball portion of the ball stud, said spring washer havinga periphery with at least one protrusion which is received in at leastone cooperating axially aligned recess in the inner cavity of thehousing or having a periphery with at least one recess which is receivedin at least one cooperating protrusion on the inner cavity of thehousing.
 7. The socket assembly of claim 6 wherein a concave side of thespring washer is positioned on the internal bearing.
 8. The socketassembly of claim 6 wherein a convex side of the spring washer ispositioned on the internal bearing.
 9. A socket assembly comprising: ahousing having an inner cavity which extends from a first open end to asecond open end; a ball stud at least partially disposed within saidinner cavity of said housing and including a shank portion and a ballportion, said shank portion extending out of said housing through saidfirst open end; an axially slidable bearing disposed in said innercavity of said housing at the second open end, said slidable bearinghaving an outer surface engaged with the inner cavity of the housing,said slidable bearing having a bearing surface that is insurface-to-surface contact with said ball portion; a cover plate closingsaid second open end of said housing; and, a spring washer positioned onthe slidable bearing for imparting a biasing force between the coverplate and the slidable bearing and the ball portion of the ball stud,said spring washer comprising a conical frustrum with an exteriorperiphery and an interior periphery, said exterior periphery having atleast one protrusion which is received in at least one axially alignedcooperating recess in the inner cavity of the housing or having anexterior periphery with at least one recess which is received in atleast one cooperating axially aligned protrusion on the inner cavity ofthe housing, said interior periphery having at least one protrusionwhich is received in at least one cooperating recess or space betweenraised teeth in the slidable bearing or having at least one recess whichis received in at least one cooperating protrusion on the slidablebearing.
 10. The socket assembly of claim 9 further including atolerance absorbing spacer formed as an annulus with a substantiallyconsistent thickness and with a plurality of substantially regularlyshaped wave forms in the axial direction and extending circumferentiallyaround the annulus, said wave forms having a constant amplitude from anoutside diameter to an inside diameter of the annulus, said tolerancespacer plastically deformed by a force applied substantially in theaxial direction leaving a controlled clearance space in the assembly,said spring washer contacting the slidable bearing and positioned belowthe tolerance absorbing spacer in the controlled clearance space. 11.The socket assembly of claim 9 wherein a concave side of the springwasher is positioned on the internal bearing.
 12. The socket assembly ofclaim 9 wherein a convex side of the spring washer is positioned on theinternal bearing.
 13. A socket assembly comprising: a housing having aninner cavity which extends from at least one open end; a ball stud atleast partially disposed within said inner cavity of said housing andincluding a shank portion and a ball portion, said shank portionextending out of said housing through said open end; an axially slidablebearing disposed in said inner cavity of said housing at the open end,said slidable bearing having an outer surface engaged with the innercavity of the housing, said slidable bearing having a bearing surfacethat is in surface-to-surface contact with said ball portion; a closurering at said open end of said housing allowing said stud to protrudethrough aperture of said closure ring; and, a spring washer positionedon the internal bearing for imparting a biasing force between theclosure ring and the internal bearing and the ball portion of the ballstud, said spring washer having an exterior periphery with at least oneprotrusion which is received in at least one cooperating axially alignedrecess in the inner cavity of the housing or having a exterior peripherywith at least one recess which is received in at least one cooperatingprotrusion on the inner cavity of the housing.
 14. The socket assemblyof claim 13 further including a tolerance absorbing spacer formed as aflat annulus with a plurality of wave forms in the axial direction andextending around the annulus, said tolerance spacer plastically deformedby a force applied substantially in the axial direction leaving acontrolled clearance space in the assembly, said spring washercontacting the slidable bearing and positioned below the toleranceabsorbing spacer in the controlled clearance space.
 15. The socketassembly of claim 14 wherein a concave side of the spring washer ispositioned on the internal bearing.
 16. The socket assembly of claim 14wherein a convex side of the spring washer is positioned on the internalbearing.
 17. A socket assembly comprising: a housing having an innercavity which extends from at least one open end; a ball stud at leastpartially disposed within said inner cavity of said housing andincluding a shank portion and a ball portion, said shank portionextending out of said housing through said open end; an axially slidablebearing disposed in said inner cavity of said housing at the open end,said slidable bearing having an outer surface engaged with the innercavity of the housing, said slidable bearing having a bearing surfacethat is in surface-to-surface contact with said ball portion; a closurering at said open end of said housing and allowing said stud to protrudethrough aperture of said closure ring; and, a spring washer positionedon the slidable bearing for imparting a biasing force between the coverplate and the slidable bearing and the ball portion of the ball stud,said spring washer comprising a conical frustrum with an exteriorperiphery and an interior periphery, said exterior periphery having atleast one protrusion which is received in at least one cooperatingaxially aligned recess in the inner cavity of the housing or having aexterior periphery with at least one recess which is received in atleast one cooperating protrusion on the inner cavity of the housing,said interior periphery having at least one protrusion which is receivedin at least one cooperating recess or space between raised teeth in theslidable bearing or at least one recess which is received in at leastone cooperating protrusion on the slidable bearing.
 18. The socketassembly of claim 17 further including a tolerance absorbing spacerformed as a flat annulus with a plurality of wave forms in the axialdirection and extending around the annulus, said tolerance spacerplastically deformed by a force applied substantially in the axialdirection leaving a controlled clearance space in the assembly, saidspring washer contacting the slidable bearing and positioned below thetolerance absorbing spacer in the controlled clearance space.
 19. Thesocket assembly of claim 18 wherein a concave side of the spring washeris positioned on the slidable bearing.
 20. The socket assembly of claim18 wherein a convex side of the spring washer is positioned on theslidable bearing.